In a large bowl, combine the nut butter and maple syrup.
Stir in the cocoa, espresso powder and salt.Add the protein powder and mix until well combined, adding water 1 teaspoon at a time, as needed. The mixture should resemble play-dough in consistency.
Stir in the cacao nibs or another add-in if using.
Line a 9x4 inch (or 8x4 inch) loaf pan with parchment or a silicone liner. Pour the batter into the pan and press it firmly into an even layer.
Allow the bars to set for a minimum of 2 hours in the refrigerator or 30 minutes in the freezer.
Use the liner to lift the bars onto a cutting board and slice into your desired shape and size.
Enjoy immediately or refrigerate for later.
Notes
LeftoversStore at room temperature for up to 3 days, in the refrigerator for up to 1 week or freeze for up to 3 months.Protein PowderPlant-based protein powders (like pea and rice) absorb more moisture than animal-based proteins so if you use an animal-based protein (such as whey or casein), don't add any water to start. If the dough is still too thin, you can add 1-2 tablespoon of ground flaxseed.If you use a flavored protein powder, ensure that it complements the flavor of the balls (such as chocolate). You may need to adjust the sweetener if your powder is sweet.*Nutrition estimate calculated based on using half pea protein isolate and half brown rice protein.